Mont. Code Ann. § 75-10-1301

The legislature finds that some properties are being contaminated with hazardous chemical residues created by the manufacture of methamphetamine and fentanyl or the consumption of methamphetamine or fentanyl. Innocent members of the public may be harmed when they are unknowingly exposed to these residues if the properties are not decontaminated prior to any subsequent rental, sale, or use of the properties. Remediation of properties has been frustrated by the lack of a decontamination standard. The purpose of this part is to protect the public health, safety, and welfare by providing specific cleanup standards and authorizing the department to establish a voluntary program that will provide for a property decontamination process that will meet state standards.